threcixty

Mazdaspeed7.. I looked at what you have done to your car, and it is suprisingly similar to my own. The only differences seem to be that you run the Turbo drivetrain, which I really should have done.. My S5 n/a tranny sucks, and Im sure it is only a matter of time before it scatters itself at a busy intersection.. Just wondering.. what do you think about taking out the exhaust sleeves?? I ported the divider out of mine, and then enlarged the sleeve itself about 1/16" all around, but was left with the ugly air injection gap. I welded it closed and then ported it back to smooth, but it would have been about 10 hours and $75 worth of carbide bits less to pull the sleeve out. I just never thought of it. As for intake, I know a bridge is the way to go, less a Pport, but a street port does seem to come close for everyday driving. Anyways, I like what you have done, and you sold me on the Megasquirt. Ill let ya know how it goes when I get it together! Thanks again for the help!

mazdaspeed7

I never said fast as a honda. Hondas are known for their incredible tuning. You cant drive a honda in any way that upsets the stock ecu with a relatively stock car. My goal was my friends S2000 in driving manners, redline, power, etc. Ive surpassed the redline, right there with power, but quite simply, Id need a much more advanced EMS to make my drivability as good as the S2000. My car still drives better than most new cars Ive driven, though. I have a few little drivability quirks, like my car is sensative to shifts, but in all honesty, its no worse than the WRX/STi, and barely worse than the S2000. It took a little getting used to for me to be able to shift all of those cars smoothly. Oh, and my low end stomps the S2000, despite the stupid tall gears I have compared to the S2000.



I used to be all about removing the sleeves, but Ive realized something since. It makes the exhaust much louder, and on top of that, its incredibly sensative to backpressure. Check out this thread about my exhaust to see how I dealt with it. But its still very loud. The exhaust offers almost no restriction, but I could still feel a loss in power when I added the 2 moroso mufflers. You notice it most in the low end, and my true dual exhaust costed me 30+ ft lbs of torque in the low end compared to this one. And power started falling off around 6k rpm simply because the backpressure was too high and the overlap was causing a lot of intake dilution. With this last exhaust, my car is still pulling hard at 9500 rpm. If I had to do it again, Id leave the sleeves in, and keep the exhaust port more reasonable. Keeping the exhaust port smaller will allow a more restrictive exhaust(quieter) with a lot less power loss. But the torque curve is so nice. It pulls good, even at 1500 rpm, the torque keeps building until 4500 rpm, and the engine just keeps pulling through 9500 rpm.



If I was keeping this engine in the car, Id switch to FD internals on the TII tranny. Im going to break 2nd gear all together if I dont get something better in there. It wont even go into 2nd half of the time shifting above 8500 now. The synchro is long past broke, Im doing damage to the gear now. The TII tranny is simply VERY unhappy above 8k rpm. Its hard to shift at 9500 rpm when it will go into gear.



BTW, if anyone wants a 9500 rpm S5 streetport, its for sale, with or without the car.

threcixty

Yeah, Ive noticed the problem with shifting the rx up high.. I'm going to swap the tranny oil from Mobil1.. (Yes, I know it is bad for the synchros) to Redline or something. Wonder if a Miata tranny is any better. btw.. I know what you are talking about with the backpressure.. I tried a RB presilencer on my car and it wouldnt pull much past 7500, but with a dynomax, it pulls a million times harder up high. It just sucks having to replace the stupid glasspack every 3 months. Ive thought about cutting the glasspack outer housing open, taking what is left of the molten glass out, and replacing it with chore-boy stainless steel wool or something. My car started out as a $250 wholesale from the friendly Mazda dealer, and has been nothing but an experiment in progress ever since! One other thing is about the aux. intake ports.. I tried the car with a JBweld "ramp" into the port, without a sleeve, and I had **** for power below 6. I replaced it with the stock sleeves, beveled the rod that goes down the middle, and put the Pineapple inserts in with mucho locktite and center-punching, and it made a HUGE difference in the driveability. It may have lost a whole 1hp up high over no sleeve, but I can pull into traffic at 5 mph in 1st, hit it, and light em up as long as I please. It is nice to hear people ask me what kind of aftermarket turbo I have on my car!

roadkill669

You could always go crazy and build a MAP signal converter. It took me a little while to figure it out. But it has a few downsides to it. You have to have a piggyback of some sort, the SAFC will work, and you have a S5, so you have a full range TPS already. The one big problem is that it isnt as accurate as a system just running a MAP. Since you convert the signal from a linear 0-5V to a exponential 2-5V, you loose a little bit accuracy. But, you spend about $20 in parts, and if you have a piggyback already, not a bad way to spend $20. You use the stock pressure sensor, the box plugs right in (the rear speakers hookup is the same as the pressure sensor, so its plug and play)



I have to find the schmatics for my converer and build another one. When I was testing it, it worked great. The signal was pretty damn close to the AFM. I never ran the car though. My ECU blew, so I went Microech.